An Ecological Study Of The Plateau Medicinal Plant Nardostachys Jatamansi

The conservation and sustainable utilization of medicinal plant resources is essential to meeting the demands for human health.Therefore,it is necessary to advance the distribution and changes of the medical plant resources knowledge to comprehensively evaluate the current sustainable utilization of medicinal plants.The plateau medicinal plant Nardostachys jatamansi is under the threat of population decline and even regional extinction,owing to its limited distribution and slow-growth characteristics,as well as the extensive market demands in the medical and cosmetic industries,and inappropriate harvesting methods.Consequently,it has been listed as critically endangered species in the IUCN Red List of Threatened Species,been included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora to strictly control its international trade.However,in China,for the lack of ecological and trade market research,Nardostachys jatamansi was first listed as a national protected wild plant in 2021.Thus,this study explored ecological issues from natural and social ecological dimensions to clarify the current status of natural populations and market trade of Nardostachys jatamansi in China: the potential distribution range of Nardostachys jatamansi in China was modeled by Max Ent,and the dominant environmental variables influencing its distribution were identified;field surveys and semi-structured social interviews were conducted in a typical representative production area,Hongyuan County in Sichuan Province,to explore the differences in the growth of Nardostachys jatamansi among different natural habitats,estimate the potential resources of Nardostachys jatamansi in Hongyuan County,and evaluate the current status of sustainable utilization of local natural Nardostachys jatamansi resources.The main results showed that:(1)At the national scale,the natural population of Nardostachys jatamansi was mainly distributed in Sichuan Province,Yunnan Province,Tibet Autonomous Region,Qinghai Province,and Gansu Province.Of these regions,the coverage of potential suitable areas in Sichuan Province was the most extensive(54.13%).At the scale of Sichuan,such coverage in Aba Tibetan and Qiang Autonomous Prefecture,the northwestern part of Sichuan,was the most aggregated.Besides,the dominant environmental variables affecting their distribution in the optimization model(FC = LQ,RM = 1)included mean diurnal range,min temperature of coldest month,precipitation of driest month,soil type,slope,and altitude.(2)In Hongyuan County,Nardostachys jatamansi was the dominant species in both the moderate(slope)and wet(swamp or riverine)natural habitats.However,the height,above-ground biomass,and Nardosinone content in the root of Nardostachys jatamansi were higher on the slopes,in that the differences in hydrothermal factors and soil conditions between the two habitat types.The significant variables affectting the above-ground biomass of Nardostachys jatamansi in Hongyuan County included altitude,mean annual temperature,precipitation of driest month,soil organic matter,and soil p H.The multiple linear regression model constructed from these variables estimated the local potential Nardostachys jatamansi resources to be 81,416.93 tons,with a phenomenon of more in the north and less in the south.(3)According to the semi-structured social interviews,the strength of ecological protection awareness and the preference for herb harvesting species had significant influence on the herb harvesting behavior of the public in Hongyuan County.The two most widely harvested herbs in the area were Nardostachys jatamansi(harvested by31.90% of the interviewed household)and Fritillaria spp.(harvested by 34.29% of the interviewed household).Furthermore,the harvesting pressure on Nardostachys jatamansi at the late stage of the harvesting period was reduced by the arrival of harvesting period of Fritillaria spp..The annual dried Nardostachys jatamansi in Hongyuan County was about 500 tons.It’s proportion of the total potential resources in the country calculated to be 0.61%.Although the ratio had not yet been above 10% of the sustainable extraction threshold,the intensity of extraction set in each specific area should still be cautious for factors such as human harvesting impacts that were difficult to quantify in the potential resource estimation.Meanwhile,the loss of local traditional knowledge of Nardostachys jatamansi and inappropriate non-selective and non-rotational harvesting methods were serious,which was not conducive to the sustainable development and utilization of Nardostachys jatamansi resources.